The results astounded her. After three days of taking only one-third of the prescribed dose of herbal pills, the pain had vanished, making her wonder if she'd found "the magic bullet of all time."

Jane-Beers spent the next decade researching the origins, myths, tightly guarded recipes and commercial applications of herbal medicine in Java, where plants have been used for medicinal purposes since prehistory. Her 2001 opus Jamu: The Ancient Art of Herbal Healing remains the only definitive English guide on the subject. It's also the most widely read outside Indonesia since Herbarium Amboinense, a catalog of plants completed by German botanist Georg Rumphius in 1690  more than three centuries earlier.

A holistic therapy based on the notion that if disease comes from nature, then so must the cure, jamu uses a dazzling array of teas, tonics, pills, creams and powders to cure  or prevent  every ailment imaginable. The ingredients are by definition cheap, widely available and simple: nutmeg to treat insomnia, guava for diarrhea, lime to promote weight loss and basil to counter body odor.

Jamu has also been used to treat cancer. In her book, Jane-Beers writes of a traditional healer in the city of Jogjakarta who apparently cured what had been diagnosed as a terminal case of cervical cancer with a tea made of betel nut, Madagascar Periwinkle and mysterious benala leaves. By combining the tea with a strict soybean diet, the patient was said to have made a full recovery in 18 months.

Sound far-fetched? A 2011 study by Virginia Tech's Department of Food Science and Technology on the soursop tree  whose leaves are used to relieve gout and arthritis in Indonesia  found evidence showing that extracts from soursop fruit inhibit the growth of human breast cancer. Vincristine, one of 70 useful alkaloids identified in Madagascar Periwinkle, radically ups the survival rate of children with leukemia, while turmeric is being looked at as a treatment for Alzheimer's.

"Western medicine tries to destroy cancer, but at the same time it destroys elements of the body. Jamu helps the body produce its own antibodies to fight the cancer by itself," says Bryan Hoare, manager at MesaStila, a wellness retreat in central Java that serves jamu shots with breakfast and employs a tabib, or indigenous healer, for private consultations. "Coming from the earth, jamu also makes you feel good. When you take it you experience a positive feeling."

But if jamu is the magic bullet, why isn't it better known in the West, where natural Asian medicines like India's ayurvedic system and Chinese herbal healing have been growing in popularity for years?

The answer can be found on the streets of Indonesia, where jamu is consumed regularly by 49% of the population, according to the country's Ministry of Health. Valued at $2.7 billion annually, the industry covers an incredibly wide gamut of products and regimens, including homemade tonics sold by street hawkers, slimming powders, cosmetics and jamu for babies and postnatal care. Yet the best sellers in terms of value are invariably the dodgiest: those claiming to boost sexual performance or suppress appetite.

"Indonesians may well have been amused when Viagra was released in 1998," Jane-Beers says, noting the popularity of brands like Kuat Lekali (Strong Man), Kuku Bima (Nail of God) and Super Biul Erection Oil. "They have had their own remedies for years."

Then there's the association between jamu and white magic. Many indigenous healers insist on dispensing jamu on auspicious dates or in conjunction with animist spells that predate the arrival of Islam in the archipelago.

Mbah Ngatrulin, a Buddhist tabib I met in Ngadas, the highest village in Java, told me that spells are the key and that jamu may as well be "mineral water." It's the kind of comment that prevents many physicians across Southeast Asia from endorsing jamu lest patients take them for quacks.

According to Charles Saerang, head of the Indonesian Jamu Entrepreneurs Association, the primary impediment to a worldwide jamu craze is that locally produced jamu products don't meet international manufacturing standards. That hasn't stopped entrepreneurs from buying raw herbal materials in Indonesia, processing them in India and Malaysia and selling them in the U.K.  a market Indonesian-made jamu products can't access. That's a double whammy for Indonesia, which loses out on value added by third parties and the chance to promote the jamu brand name abroad.

It's impossible to say when, or even if, jamu painkillers will be stocked at supermarkets and convenience stores in countries like the U.K. Yet inroads are already being made by small businesses like the Origin Spa in Melbourne. There, highly skilled practitioners apply massage techniques developed by 16th century Indonesian royalty  the founders of modern jamu  using creams and oils containing turmeric, betel leaves and crushed eggshells. There's a minimum two-month waiting list for Origin's five-day post-pregnancy treatment that is said to help women regain their figures quickly, improve lactation and dispel wind, dizziness and aches and pains.

"It's surprisingly popular with the Asian mums throughout Australia," says partner Jessica Koh. "But it's still unfamiliar to most of the locals."